And it suggests this object because it, the typical element, is a common point that links together the various cases and the various presentations in which the object is given to us. In this sense it is a universal or an identity. How can this conception of a logical idea be applied to a perfectly simple presentation? It would be impossible so to apply it, but there does not seem to be such a thing as a simple presentation in the sense of a presentation that has no connection as a universal with anything else. In the image of a particular blue colour, we cannot indeed separate out what makes it blue from what makes it the particular {78} shade of blue that it is. But nevertheless its blueness makes it a symbol to us of blue in general, and when so thought of, crushes out of sight all the visible peculiarities that attend every spatial surface. We understand perfectly well that the colour is blue, and that in saying this we have gone beyond the limits of the momentary image, and have referred something in it as a universal quality to our world of objects. An idea, in this sense, is both less and more than a psychical image. It contains less, but stands for more. It includes only what is central and characteristic in the detail of each mental presentation, and therefore omits much. But it is not taken as a mental presentation at all, but as a content belonging to a systematic world of objects independent of my thought, and therefore stands for something which is not mere psychical image. If therefore we are asked to display it as an image, as something fixed in a permanent outline, however pale or meagre, we cannot do so. It is not an abstract image, but a concrete habit or tendency. It can only be displayed in the judgment, that is, in a concrete case of reference to reality. Apart from this, it is a mere abstraction of analysis, a tendency to operate in a certain way upon certain psychical presentations. Psychically speaking, it is when realised in judgment a process more or less systematic, extending through time, and dealing with momentary presentations as its material. In other words, we may describe it as a selective rule, shown by its workings but not consciously before the mind--for if it were, it would no longer be an idea, but an idea of an idea. Every judgment, whether made with language or without, {79} is an instance of such an idea, which may be called a symbolic idea as distinct from a psychical image; “symbolic” because the mental units or images involved are not as such taken as the whole of the object for which they stand, but are in a secondary sense, as the word in a primary sense, symbols or vehicles only.